1. Field of the Invention
The present invention relates to a method for changing the program of each transmission system constituting a network, and more particularly to a method for changing the program of each transmission system in a remote place.
2. Description of the Related Art
In general, a communication network basically includes a plurality of nodes with a switching function being connected via transmission paths to communication terminals. A group of systems is configured in such a manner to build a network. This network includes an exchange network allowing a plurality of switching systems to be connected to each other, a transmission network allowing a plurality of transmission systems to be connected to each other, a network allowing a plurality of external terminals such as personal computers (PCs) to be connected to each other within a specific region via a local area network (LAN), and an Internet network allowing a plurality of remote computers to be accessed to communicate with each other over the Internet.
In building a network as mentioned above, the network is classified into a variety of types depending on the characteristics of the networks. The name of the networks also varies based on the constituting elements of each of the networks. Further, the network is configured in such a manner that a network management system for the maintenance and repair of network is provided to centrally control these networks. The scope of the network is represented by a combination of nodes and links representing a network topology. There are two types of methods in implementing a network: (1) a method for implementing a network by using a loop-shaped network topology; and, (2) a method for implementing a network by using a linear-shaped network topology.
FIG. 1 is a schematic view illustrating the flow stream of data and control signals for changing the program in the loop-shaped transmission network according to the prior art.
A process for changing the program in the loop-shaped transmission network will be described in detail hereinafter with reference to FIG. 1. In FIG. 1, each of transmission systems constituting the transmission network forms one node, respectively. Namely, a transmission system, i.e., a Network Element 1 (hereinafter referred as “NE 1 (21)”) forming a first node is connected to a transmission system, i.e., a Network Element 2 (hereinafter referred as “NE 2 (22)”) forming a second western node. The NE 1 is connected to a transmission system, i.e., a Network Element 3 (hereinafter referred as “NE 3 (23)”) forming a third eastern node. Also, a transmission system, i.e., a Network Element 4 (hereinafter referred as “NE 4 (24)”) forming a fourth northern node is coupled between the NE 2 (22) and NE 3 (23). A Network Management System 10 (hereinafter referred as “NMS”) is connected to the NE 1 (21).
According to the above configuration, if the NMS 10 attempts to change the program for each of the nodes (21), (22), (23), and (24) arranged in the loop-shaped transmission network, the program of the NE 1(21) is changed first. To this end, the NMS 10 transmits a control signal, indicated by a dotted line in FIG. 1, and the new program to the NE 1 (21). After the program of the NE 1 (21) is changed into the new program transmitted from the NMS 10. The NMS 10 transmits the new program and the control signal to the NE 2 (22) via the NE 1 (21), so that the program of the NE 2 (22) can be also changed to the new program. Similarly, the NMS 10 transmits the new program and the control signal to the NE 3 (23) via the NE 1 (21), so that the program of the NE 3 (23) is changed into the new program. Then, the NMS 10 transmits the new program data and the control signal to the NE 4 (24) via the NE 1 (21) and the NE 2 (22), or the NE 1 (21) and the NE 3 (23) so that the program of the NE 4 (24) is changed into the new program.
Accordingly, if data representing the new changing program is transmitted to each of the nodes (21), (22), (23) and (24), a great deal of traffic for the data transmission of the new changing program and the control signal is generated between the NMS 10 and the NE 1 (21), between the NE 1 (21) and the NE 2 (22), or between the NE 1 (21) and the NE 3 (23). Thus, the number of traffic hops for each of the nodes in the loop-shaped transmission network can be expressed by the following [formula 1]:H=(N+3)×N+1, (if N is an odd number);H=(N+2)×N, (if N is an even number),  [formula 1]
wherein H is the number of traffic hops and N is the number of nodes (transmission systems) arranged in the loop-shaped transmission network. As the number of nodes increases, the number of traffic hops also increases, thereby degrading the transmission efficiency in the loop-shaped transmission network.
FIG. 2 is a schematic view illustrating the flow stream of data and control signals for changing the program in a linear-shaped transmission network according to the prior art.
A process for changing the program in the linear-shaped transmission network will be described in detail hereinafter with reference to FIG. 2. In FIG. 2, an NMS 10 is connected to a transmission system, i.e., NE 1 (21) forming a first node, which is connected to a transmission system, i.e., NE 2 (22) forming a second node, which is also connected to a transmission system, i.e., NE 3 (23) forming a third node. In the event that the NMS 10 attempts to change the program of each of the nodes (21), (22), (23) and (24) arranged in the linear-shaped transmission network, the program of the NE 1 (21) first should be changed. Thus, the NMS 10 transmits the control signal, indicated by a dotted line in FIG. 2, along with data representing the new program to the NE 1 (21). In this manner, after the program of the NE 1 (21) is changed to the new program data transmitted from the NMS 10, the NMS 10 transmits the new program data and the control signal to the NE 2 (22) via the NE 1 (21), so that the program of the NE 2 (22) is also changed to the new program. Similarly, the NMS 10 transmits the new program data and the control signal to the NE 3 (23) via the NE 1 (21) and the NE 2 (22), so that the program of the NE 3 (23) is changed to the new program. Through this process, the program of transmission system forming each node is changed to the new program. Accordingly, the number of traffic hops of the nodes of the linear-shaped transmission network can be expressed by the following [formula 1]:
                    H        =                              {                          N              +                              (                                  N                  +                  1                                )                                      }                    2                                    [                  formula          ⁢                                          ⁢          1                ]            
wherein H is the number of traffic hops, and N is the number of nodes (transmission systems) arranged in the linear-shaped transmission network. Therefore, as the number of nodes increases as in the case of loop-shaped transmission network, the number of traffic hops increases, thereby degrading transmission efficiency in the linear-shaped transmission network.
The networking architecture arranged in the loop-shaped transmission network and linear-shaped transmission network as mentioned-above is configured in such a manner that, if the NMS 10 attempts to change the program of each of the nodes (21), (22), (23), and (24) constituting the transmission network in a remote place, the NMS 10 centrally transmits the new program data and the control signal to each node, resulting in an increase in the number of traffic hops and thereby degrading the transmission efficiency in the transmission networks.